So that the drivers are able to implement static singleton instance for some special domains. The blocking domain is an example. The driver has no need to allocate different memory for each blocking domain allocation request. Hence, no need for a free callback. Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Tested-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx> Tested-by: Tony Zhu <tony.zhu@xxxxxxxxx> --- drivers/iommu/iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index e985f4d5895f..630e1b64ed89 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1972,7 +1972,8 @@ void iommu_domain_free(struct iommu_domain *domain) if (domain->type == IOMMU_DOMAIN_SVA) mmdrop(domain->mm); iommu_put_dma_cookie(domain); - domain->ops->free(domain); + if (domain->ops->free) + domain->ops->free(domain); } EXPORT_SYMBOL_GPL(iommu_domain_free); -- 2.25.1
